Spina Bifida (SB) is a congenital neural tube defect that involves the incomplete development of the spinal cord, resulting in varying health ailments. Studies focusing on physical activity (PA) levels among youth with SB are limited, but have demonstrated that this group is even more inactive than their typically developing peers. Given the high obesity rates and sedentary lifestyle that are commonly reported among youth with SB, research is needed to identify strategies to facilitate PA participation in this population. The purpose of this study was to apply Michie et al.'s 2005 Theoretical Domains Framework to qualitatively explore the barriers and facilitators influencing PA participation in a sample of youth (ages 12-17 years) with SB. Nine eligible youth (6 females; mean age = 15.9 years) took part in an individual semi-structured interview. Interviews were audio-recorded and transcribed verbatim, and a thematic analysis was conducted. The most commonly reported perceived PA facilitators were: self-efficacy, positive consequences of PA, positive affect, and social influences. Lack of knowledge and independence, pain/fatigue, limited control over decision processes, and inaccessible environmental resources were the most commonly reported barriers to PA. These findings provide useful avenues to guide future theory-based PA intervention research through the identification of potential theoretical correlates to target that are specific to youth with SB.